Two world's famous prisoners 'Colditz' and 'Pascal' are locked in a cell.
They plan to escape from the cell.
They noticed there is an open window at 40 feet above the ground level.
Both of them tried very hard but are never able to reach there.

Then both of them decided to plan to escape by a tunnel and they start digging out.
After digging for just 5 days, Colditz and Pascal comes out with the much more easier plan than tunneling and they escaped.

Explanation:
It's a maths magical square root series as :
Square root of number 121 is 11
Square root of number 12321 is 111
Square root of number 1234321 is 1111
Square root of number 123454321 is 11111
Square root of number 12345654321 is 111111
Square root of number 1234567654321 is 1111111
Square root of number 123456787654321 is 11111111
Square root of number 12345678987654321 is 111111111 (answer)

As you can notice in the picture that ten coins have been arranged to form a triangle pointing upwards. What you have to do is move three coins and make that triangle point downwards. Can you do it in just 3 moves?

You have two cubes with plane faces. You have to mark both the cubes with numbers in a manner that all the days of a month can be portrayed using those cubes. Also, note that you have to use both the cubes for displaying any date. Suppose if you have to display the 5th day of the month, you will have to display it as 05.